In 1839, the Ontario government passed "An Act to Authorise the Erection of an Asylum within this Province for the Reception of Insane and Lunatic Persons."

This legislation gave the Government of Ontario the authority to establish the first provincial asylum for people with a developmental disability.

In 1876, Ontario opened its first institution for people with a developmental disability on the outskirts of Orillia. In 1876, it was named the Orillia Asylum for Idiots. Later it was called the Ontario Hospital School, Orillia.(1) At the time of its closure in 2009, the facility was known as the Huronia Regional Centre.

By 1890, the Orillia facility had 309 residents. By 1902, that number had risen to 652. At its peak in 1968, it had 2,600 residents.

More institutions followed, often due to an increase in demand. In 1905, the government opened the Oxford Regional Centre in Woodstock. D'Arcy Place in Cobourg opened in 1920. By the mid 1970s, the government operated 16 institutions for individuals with a developmental disability. At their peak in 1974, more than 10,000 people lived in them, both children and adults.

From the opening of the first institution in 1876 to the closure of the last ones in 2009, over 50,000 people with a developmental disability had lived in these institutions.

(1) Ontario's institutions for people with a developmental disability were originally known as Ontario Hospital Schools.